title: High average power large-pitch fiber amplifier with robust single-mode operation.
abstract: Ytterbium-doped large-pitch fibers with very large mode areas are investigated in a high-power fiber amplifier configuration. An average output power of 294 W is demonstrated, while maintaining robust single-mode operation with a mode field diameter of 62 μm. Compared to previous active large-mode area designs, the threshold of mode instabilities is increased by a factor of about 3.
authors.affiliation: Friedrich-Schiller-University Jena, Institute of Applied Physics, Jena, Germany. fabian.stutzki@uni-jena.de
authors.forename: Fabian
authors.initials: F
authors.lastname: Stutzki
authors.forename: Florian
authors.initials: F
authors.lastname: Jansen
authors.forename: Tino
authors.initials: T
authors.lastname: Eidam
authors.forename: Alexander
authors.initials: A
authors.lastname: Steinmetz
authors.forename: Cesar
authors.initials: C
authors.lastname: Jauregui
authors.forename: Jens
authors.initials: J
authors.lastname: Limpert
authors.forename: Andreas
authors.initials: A
authors.lastname: Tünnermann